Average Error: 0.3 → 0.2
Time: 5.4s
Precision: 64
\[\frac{\left(d1 \cdot d2\right)}{\left(d1 \cdot d3\right)}\]
↓
\[\left(\frac{d3}{d2}\right) \cdot d1\]
\frac{\left(d1 \cdot d2\right)}{\left(d1 \cdot d3\right)}
↓
\left(\frac{d3}{d2}\right) \cdot d1
double f(double d1, double d2, double d3) {
        double r4784389 = d1;
        double r4784390 = d2;
        double r4784391 = r4784389 * r4784390;
        double r4784392 = d3;
        double r4784393 = r4784389 * r4784392;
        double r4784394 = r4784391 + r4784393;
        return r4784394;
}
↓
double f(double d1, double d2, double d3) {
        double r4784395 = d3;
        double r4784396 = d2;
        double r4784397 = r4784395 + r4784396;
        double r4784398 = d1;
        double r4784399 = r4784397 * r4784398;
        return r4784399;
}

Error

Bits error versus d1

Bits error versus d2

Bits error versus d3

Derivation

  1. Initial program 0.3

    \[\frac{\left(d1 \cdot d2\right)}{\left(d1 \cdot d3\right)}\]

  2. Simplified0.2

    \[\leadsto \color{blue}{\left(\frac{d3}{d2}\right) \cdot d1}\]

  3. Final simplification0.2

    \[\leadsto \left(\frac{d3}{d2}\right) \cdot d1\]

Reproduce

herbie shell --seed 2019168 
(FPCore (d1 d2 d3)
  :name "FastMath dist"
  (+.p16 (*.p16 d1 d2) (*.p16 d1 d3)))